The present invention provides a pharmaceutical composition and method for treating diseases characterized by activation of an inflammatory cytokine cascade, particularly sepsis, including septic shock and ARDS (acute respiratory distress syndrome), comprising administering an effective amount of an antagonist to the high mobility group 1 protein (HMG1). The present invention further provides a diagnostic method for monitoring the severity of sepsis and related conditions, comprising measuring the serum concentration of HMG1 in a patient exhibiting symptoms of a disease characterized by activation of inflammatory cytokine cascade. Lastly, the present invention provides a pharmaceutical composition and method for effecting weight loss or treating obesity, comprising administering an effective amount of an HMG1 protein or a therapeutically active fragment of the gene product of an HMG1 gene.
Sepsis is an often fatal clinical syndrome that develops after infection or injury. Sepsis is the most frequent cause of mortality in hospitalized patients. Experimental models of gram negative sepsis based on administration of bacterial endotoxin (lipopolysaccharide, LPS) have led to an improved understanding of the pathogenic mechanisms of lethal sepsis and conditions related to sepsis by virtue of the activation of a common underlying inflammatory cytokine cascade. This cascade of host-response mediators includes TNF, IL-1, PAF and other macrophage-derived factors that have been widely studied as acute, early mediators of eventual lethality in severe endotoxemia (Zhang and Tracey, In The Cytokine Handbook, 3rd ed. Ed. Thompson (Academic Press Limited, USA). 515-547, 1998).
Unfortunately, therapeutic approaches based on inhibiting these individual xe2x80x9cearlyxe2x80x9d mediators of endotoxemia have met with only limited success in large prospective clinical trials against sepsis in human patients. It is possible to infer from these disappointing results that later-appearing factors in the host response might critically determine pathogenesis and/or lethality in sepsis and related disorders. Accordingly, there is a need to discover such putative xe2x80x9clatexe2x80x9d mediators necessary and/or sufficient for part or all of the extensive multisystem pathogenesis, or for the lethality, of severe endotoxemia, particularly as endotoxemia is representative of clinical sepsis and related clinical disorders.
HMG1 is a 30 kDa chromosomal nucleoprotein belonging to the burgeoning high mobility group (HMG) of non-histone chromatin-associated proteins. As a group, the HMG proteins recognize unique DNA structures and have been implicated in diverse cellular functions, including determination of nucleosome structure and stability, as well as in transcription and/or replication. The HMG proteins were first characterized by Johns and Goodwin as chromatin components with a high electrophoretic mobility in polyacrylamide gels (see in The HMG Chromosomal Proteins, E. W. Johns, Academic Press, London, 1982). Higher eukaryotes exhibit three families of HMG proteins: the HMG-1/-2 family, the HMG-14/-17 family and the HMG-I/-Y family. Although the families are distinguishable by size and DNA-binding properties, they are similar in their physical properties. HMG proteins are highly conserved across species, ubiquitously distributed and highly abundant, and are extractable from chromatin in 0.35 M NaCl and are soluble in 5% perchloric or trichloroacetic acid. Generally, HMG proteins are thought to bend DNA and facilitate binding of various transcription factors to their cognate sequences, including for instance, progesterone receptor, estrogen receptor, HOX proteins, and Oct1, Oct2 and Oct6. Recently, it has become apparent that a large, highly diverse group of proteins including several transcription factors and other DNA-interacting proteins, contain one or more regions similar to HMG1, and this feature has come to be known as the HMG1 box or HMG1 domain. cDNAs coding for HMG1 have been cloned from human, rat, trout, hamster, pig and calf cells, and HMG1 is believed to be abundant in all vertebrate cell nuclei. The protein is highly conserved with interspecies sequence identities in the 80% range. In chromatin, HMG1 binds to linker DNA between nucleosomes and to a variety of non-xcex2-DNA structures such as palindromes, cruciforms and stem-loop structures, as well as cisplatin-modified DNA. DNA binding by HMG1 is generally believed to be sequence insensitive. HMG1 is most frequently prepared from washed nuclei or chromatin, but the protein has also been detected in the cytoplasm. (Reviewed in Landsman and Bustin, BioEssays 15:539-546, 1993; Baxevanis and Landsman, Nucleic Acids Research 23:514-523, 1995). To date, no link has been established between the HMG proteins and any clinical condition or disease.
HMG1 has been alternatively identified as a heparin-binding protein abundantly expressed in developing brain and dubbed xe2x80x9camphoterinxe2x80x9d for its highly dipolar sequence, comprising two internal repeats of a positively charged domain of about 80 amino acids (the HMG1 box) and an acidic C-terminal domain containing a stretch of approximately 30 continuous glutamic or aspartic acid residues. Amphoterin/HMG1 has been localized to the outer surface of the plasma membranes of epithelial, and especially neuronal cells, where it has been specifically localized to the filipodia of neural cells. Inhibition studies have suggested that amphoterin/HMG1 is required for process (neurite) extension and amphoterin/HMG1 also may be involved in neuron-glia interactions (Merenmies et al., J. Biol. Chem. 266:16722-16729,1991; Merenmies et al., J. Biol. Chem. 266:16722-16729, 1991; Milev et al., J. Biol. Chem. 273:6998-7005, 1998; and Salmivirta et al., Exp. Cell Res. 200:444-451, 1992). Amphoterin/HMG1 can be released from murine erythroleukemia cells after stimulation with the chemical inducer hexamethylenebisacetamide (Melloni et al., Biochem. Biophys. Res. Commun. 210:82-89, 1995). Previous study suggested that the gene product of the HMG1 gene functions as a differentiation enhancing factor by stimulating xcex1-PKC (Melloni et al., Biochem. Biophys. Res. Commun. 210:82-89, 1995; and Melloni et al., FEBS Lett. 368:466-470, 1995).
The HMG1 gene product has been shown to interact with plasminogen and tissue-type plasminogen activator (t-PA) and effectively enhance plasmin generation at the cell surface, a system that is known to play a role in extracellular proteolysis during cell invasion and tissue remodeling. Amphoterin/HMG1 has also been shown to interact with the receptor of advanced glycosylation end products (RAGE) (Mohan et al., Biochem. Biophys. Res. Commun. 182:689-696, 1992; Yamawaki et al., J. Neurosci. Res. 44:586-593, 1996; Salmivirta et al., Exp. Cell Res. 200:444-451, 1992; and Vassalli et al., J. Clin. Invest. 88:1067-1072, 1991), (Redlitz and Plow, Baillieres Clin. Haematol. 8:313-327, 1995; and Parkkinen et al., J. Biol. Chem. 266:16730-16735, 1991).
There is a longstanding need in the art to discover improved agents that can prevent the cytokine-mediated inflammatory cascade and have therapeutic activity in a large variety of cytokine-mediated inflammatory diseases. The present invention was made during the course of investigative research to identify agents that mediate toxicity, pathogenesis and/or lethality in sepsis and other disorders related by a common activation of the inflammatory cytokine cascade.
Diseases and conditions mediated by the inflammatory cytokine cascade are numerous. Such conditions include the following grouped in disease categories:
Systemic Inflammatory Response Syndrome, which includes:
Sepsis syndrome
Gram positive sepsis
Gram negative sepsis
Culture negative sepsis
Fungal sepsis
Neutropenic fever
Urosepsis
Meningococcemia
Trauma hemorrhage
Hums
Ionizing radiation exposure
Acute pancreatitis
Adult respiratory distress syndrome (ARDS)
Reperfusion Injury, which includes
Post-pump syndrome
Ischemia-reperfusion injury
Cardiovascular Disease, which includes
Cardiac stun syndrome
Myocardial infarction
Congestive heart failure
Infectious Disease, which includes
HIV infection/HIV neuropathy
Meningitis
Hepatitis
Septic arthritis
Peritonitis
Pneumonia Epiglottitis
E. coli 0157:H7
Hemolytic uremic syndrome/thrombolytic thrombocytopcnic purpura
Malaria
Dengue hemorrhagic fever
Leishmaniasis
Leprosy
Toxic shock syndrome
Streptococcal myositis
Gas gangrene
Mycobacterium tuberculosis
Mycobaclerium aviun intracellulare 
Pneumocystis carinii pneumonia
Pelvic inflammatory disease
Orchitis/epidydimitis
Legionella
Lyme disease
Influenza A
Epstein-Barr Virus
Viral associated hemiaphagocytic syndrome
Viral encephalitis/aseptic meningitis
Obstetrics/Gynecology, including:
Premature labor
Miscarriage
Infertility
Inflammatory Disease/Autoimmunity, which includes:
Rheumatoid arthritis/seronegative arthropathies
Osteoarthritis
Inflammatory bowel disease
Systemic lupus erythematosis
Iridoeyelitis/uveitistoptic neuritis
Idiopathic pulmonary fibrosis
Systemic vasculitis/Wegener""s gramilornatosis
Sarcoidosis
Orchitis/vasectomy reversal procedures
Allergic/Atopic Diseases, which includes:
Asthma
Allergic rhinitis
Eczema
Allergic contact dermatitis
Allergic conjunctivitis
Hypersensitivity pneumonitis
Malignancy, which includes:
ALL
AML
CML
CLL
Hodgkin""s disease, non-Hodgkin""s lymphoma
Kaposi""s sarcoma
Colorectal carcinoma
Nasopharyngeal carcinoma
Malignant histiocytosis
Paraneoplastic syndrome/hypercalcemia of malignancy
Transplants, including:
Organ transplant rejection
Graft-versus-host disease
Cachexia
Congenital, which includes:
Cystic fibrosis
Familial hematophagocytic lymphohistiocytosis
Sickle cell anemia
Dermatologic, which includes:
Psoriasis
Alopecia
Neurologic, which includes:
Multiple sclerosis
Migraine headache
Renal, which includes:
Nephrotic syndrome
Hemodialysis
Uremia
Toxicity, which includes:
OKT3 therapy
Anti-CD3 therapy
Cytokine therapy
Chemotherapy
Radiation therapy
Chronic salicylate intoxication
Metabolic/Idiopathic, which includes:
Wilson""s disease
Hemachromatosis
Alpha-1 antitrypsin deficiency
Diabetes
Hashimoto""s thyroiditis
Osteoporosis
Hypothalamic-pituitary-adrenal axis evaluation
Primary biliary cirrhosis
The present invention provides a pharmaceutical composition for treating conditions (diseases) mediated by the inflammatory cytokine cascade, comprising an effective amount of an antagonist or inhibitor of HMG1. Preferably, the HMG1 antagonist is selected from the group consisting of antibodies that bind to an HMG1 protein, HMG1 gene antisense sequences and HMG1 receptor antagonists. The present invention provides a method for treating a condition mediated by the inflammatory cytokine cascade, comprising administering an effective amount of an HMG1 antagonist. In another embodiment, the inventive method further comprises administering a second agent in combination with the HMG1 antagonist, wherein the second agent is an antagonist of an early sepsis mediator, such as TNF, IL-1xcex1, IL-1xcex2, MIF or IL-6. Most preferably, the second agent is an antibody to TNF or an IL-1 receptor antagonist (IL-1ra).
The present invention further provides a diagnostic and prognostic method for monitoring the severity and predicting the likely clinical course of sepsis and related conditions for a patient exhibiting shock-like symptoms or at risk to exhibit symptoms associated with conditions mediated by the inflammatory cascade. The inventive diagnostic and prognostic method comprises measuring the concentration of HMG1 in a sample, preferably a serum sample, and comparing that concentration to a standard for HMG1 representative of a normal concentration range of HMG1 in a like sample, whereby higher levels of HMG1 are indicative of poor prognosis or the likelihood of toxic reactions. The diagnostic method may also be applied to other tissue or fluid compartments such as cerebrospinal fluid or urine. Lastly, the present invention provides a pharmaceutical composition and method for effecting weight loss or treating obesity, comprising administering an effective amount of HMG1 or a therapeutically active fragment thereof